1. Technical Field
The present invention relates to a light-emitting device and a projector.
2. Related Art
One known light-emitting device is obtained by forming a light-emitting layer made of a group-III nitride semiconductor on a substrate, injecting a current from an external portion, and combining electrons and holes inside the light-emitting layer so as to emit light. In such a light-emitting device, a strain may be generated between the light-emitting layer and the substrate. Particularly, when InGaN is used in the light-emitting layer, and materials other than InGaN (for example, GaN) are used in the substrate, a lattice mismatch therebetween is generated and the strain increases. When such a strain is generated, an electric field due to a piezoelectric field (piezoelectric field) is applied to the light-emitting layer, and a radiative recombination probability between the electrons and the holes is remarkably reduced.
To address the above problem, for example, there has been proposed a method for relaxation of a strain generated between the light-emitting layer and the substrate by forming the group-III nitride semiconductor using a fine columnar crystal structure as disclosed in JP-A-2008-169060.
However, according to the technique disclosed in JP-A-2008-169060, a side surface having a fine columnar crystal structure is exposed. Therefore, non-radiative recombination caused by an impurity or a defect near the side surface occurs, and the light-emitting efficiency may be degraded.